Abstract

The paper addresses the implementation of advanced process control (APC) and monitoring the economic performance for ammonia production facility relying on natural gas steam reforming. The plant profit optimization was the main goal in the development of a custom APC structure by using a programmed feedforward–ratio–cascade control scheme. The ammonia plant model constructed by UniSim Design software gave a basis for the implementation of a closed-loop control. Ammonia production rate set point acts as the primary/master while holding the steam-to-natural gas and air-to-natural gas molar ratios as secondary/slave controllers. Moreover, the paper considers the main process disturbances on the controlled and manipulated variables. The APC controller with economic objective function ensured better disturbance rejection, more efficient operation of the whole ammonia plant, and increased profitability of up to 7%.

摘要

本文讨论了先进过程控制 (APC) 的实施和监测依赖天然气蒸汽重整的氨生产设施的经济性能。工厂利润优化是通过使用编程的前馈-比率-串级控制方案开发定制 APC 结构的主要目标。UniSim Design 软件构建的合成氨装置模型为实现闭环控制奠定了基础。氨生产速率设定点充当主要/主控制器，同时保持蒸汽与天然气和空气与天然气的摩尔比作为辅助/从控制器。此外，本文还考虑了受控变量和受控变量的主要过程扰动。具有经济目标函数的 APC 控制器确保了更好的抗扰性，